As her career path stagnates, Jane Tennison, now 54, feels pressured to consider her future. She copes with "modern" policing, including her current supervisor who was once junior to her. While dealing with 24 murder cases simultaneously, she decides to personally assume leadership into the investigation into the cruel murder of a Bosnian Muslim refugee. As the team uncovers evidence of the victims and perpetrators of past crimes in the Yugoslav Wars, the prime suspect is a security guard of Serbian heritage.